* Shell sells interests in new, existing oil sands projects
* Buys half of Marathon Oil Canada
* Total deal value of $7.25 bln to Shell
* Ties 10 pct of directors' bonuses to emissions management
* CEO's pay rose 60 pct in 2016 (Adds details, background)
By Karolin Schaps
LONDON, March 9 (Reuters) - Royal Dutch Shell has agreed to sell most of its Canadian oil sands assets for $8.5 billion, the latest international oil major to withdraw from the costly projects, which are among the most carbon heavy.
Shell is trying to sell assets totalling $30 billion to cut debt following its $54 billion acquisition of BG Group and is under investor pressure to mitigate climate change risks.
As well as revealing the Canadian oil sands sale, Shell also said on Thursday that ten percent of directors' bonuses will now be tied to how well it manages greenhouse gas emissions in refining, chemical and upstream.
Analysts welcomed the deal, under which Shell has agreed to sell its existing and undeveloped Canadian oil sands interests to Canadian Natural and to cut its share in the Athabasca Oil Sands Project (AOSP) from 60 to 10 percent.
"This significant divestment should help de-gear Shell's balance sheet over 2017 and help remove concerns around the dividend," Biraj Borkhataria of RBC Capital Markets said.
Shell is also buying half of Marathon Oil Canada Corporation which brings the deal's value to Shell to $7.25 billion and its divestment plan total to around $20 billion as it works towards its target of $30 billion by late 2018.
Other oil firms including Exxon Mobil, Conoco Phillips and Statoil have written down or sold their Canadian oil sand assets.
Shell said it would remain as operator of the AOSP Scotford upgrader and the Quest carbon capture and storage project.
Shares in Shell were trading 1.1 percent lower at 0852 GMT, in line with the sector index that was down 1.2 percent.
The company is also replacing earnings per share in directors' long-term incentives with free cashflow, saying its disposals programme had made it a more important metric.
In its annual report, Shell said its Chief Executive Ben van Beurden saw his pay jump 60 percent to 8.263 million euros ($8.7 million) in 2016, the year he pulled off the BG purchase. ($1 = 0.9482 euros) (Editing by Jason Neely and Alexander Smith)